1. Field of the Invention
The present invention relates generally to the field of semiconductor processing and, more particularly, to the monitoring and detection of defects in connection with the fabrication of semiconductor devices.
2. Description of the Prior Art
In the semiconductor industry an important consideration is the yield as a percentage of tested acceptable chips per wafer. This percentage is directly related to the profitability of the manufacturer. One factor influencing the yield is the quality of the raw material, including the density of surface defects (number per cm2). Another factor is the number of surface defects introduced by the manufacturing process (including chemical and mechanical polishing).
Surface defects need to be made visible to assess further treatment for ideally eliminating the defects. The sizes of these defects can be in the range below 0.1 nanometer or 1,000 angstroms (Å). For the detection and monitoring of defects below 0.1 nanometer, high-sensitivity, expensive monitoring equipment may be needed which for example may be more suited for laboratory rather than production applications. It would be desirable to be able to detect defects sized below 0.1 nanometer with commonly used low-sensitivity monitoring equipment.